Methods and apparatuses for performing wireless charging are disclosed. One of the disclosed apparatuses is a wireless power transmitter which can receive charging power from a wireless power transmitter. When the wireless power transmitter detects a transition from a Stand Alone (SA) mode to a Non Stand Alone (NSA) mode, it generates a message that includes address information used to re-connect with the wireless power transmitter and transmits the message to the wireless power transmitter.